Process for refining hydrocarbons with boron trifluoride and oxygen



United States Patent PROCESS FOR REFINING HYDROCARBONSWITH .BORON TRIFLUORIDE AND OXYGEN Archibald P. Stuart, Media, Pa., assignor to Sun Oil Cornpany, Philadelphia, Pa., a corporation of New Jersey No Drawing. Application June 22, 1955, Serial No. 517,365

7 Claims. (Cl. 196--29) This invention relates to a process for refining hydrocarbon materials containing one or more undesirable rimpurities. More particularly, the invention relates to a process for removing non-hydrocarbons, such as sulfur compounds, from admixtures thereof with hydrocarbons, such as petroleum oil fractions containing sulfur compounds.

Various processes for removing non-hydrocarbons from hydrocarbon materials have heretofore been described. It is known, for example, to treat hydrocarbon oils with BF either alone or as a complex with another material 'such as an oxygenated organic compound. After the BF treatment such processes generally require a neutralization step, which is accomplished by washing the treated hydrocarbon material with an aqueous caustic solution :or by treating with ammonia gas. Such processes, however, while effective for removing a portion of the non-hydrocarbons have generally been unsatisfactory in that a refined product that is stable to oxidation is .not obtained.

It has now been found that a refined, stable hydrocarbon product can be obtained from a mixture of a hydrocarbon material and one or more non-hydrocarbon materials by treating the mixture with BF, and simultaneously, or subsequently, contacting the BF treated hydrocarbon material with oxygen.

In an embodiment of the process of the invention, a hydrocarbon material mixed with one or more non-hydrocarbon materials is treated with BB, and is subsequently contacted with oxygen. The B1 treatment converts a large proportion of the non-hydrocarbons to materials insoluble in the hydrocarbon material. The insoluble material separates from the body of the hydrocarbon material as a sludge. The BF treated hydrocarbon material is then contacted with oxygen such as by bubbling an oxygen-containing gas, preferably air, through the hydrocarbon material. As has been found, the quantity of sludge is increased by the oxygen contacting. The soformed sludge is then separated from the body of hydrocarbon material, and the resulting hydrocarbon material is the refined, stable hydrocarbon product of the process of the invention.

While it is not known with certainty why the process of the invention is remarkably effective when producing a highly refined stable hydrocarbon product, it is believed that while a large proportion of the reaction products of BF with non-hydrocarbons is insoluble in the hydrocarbon material, at least a portion of such reaction product is soluble in the hydrocarbon material. Such soluble reaction products are not separated in heretofore used processes and appear as impurities in the final product. In the process of the present invention, such soluble reaction products of BF are converted to insoluble materials by contacting with oxygen, and are hence con verted to sludge which is separated with the sludge formed by the initial BF treatment.

In another embodiment of the process of the inven tion, BF and oxygen are simultaneously contacted with the hydrocarbon material being treated. In this embodiment, the BE, and oxygen may be admixed prior to their introduction into the hydrocarbon material, or they may be introduced simultaneously but separately therein.

In a further embodiment of the process, a hydrocarbon material containing non-hydrocarbons is treated with BF to form a sludge. The so-formed sludge is separated such as by decanting or centrifuging. The separated rhydrocarbon material containing the soluble portion of the reaction products of BF and the non-hydrocarbons is then contacted with oxygen such as by bubbling air therethrough. On contacting with oxygen, additional sludge is formed due to the conversion of the soluble-reaction products of BF, and non-hydrocarbons to insoluble materials. 'This sludge is thereafter separated from the hydrocarbon material by any convenient means, such as by decanting or centrifuging.

After the final separation of sludge, regardless of the embodiment of the process employed, it is generally advantageous to wash the treated hydrocarbon material with water and to dry the Washed hydrocarbon material. The washing step is conveniently accomplished by intimately contacting water with the hydrocarbon materials continuously in an extraction tower, or batchwise by mechanical mixing, allowing the Water to form a separate phase, and decanting. The drying step is conveniently accomplished by passing an inert gas such as flue gas or nitrogen through the washed hydrocarbon materials, preferably at an elevated temperature, but other drying means known to .the art can be employed if desired.

Hydrocarbon materialscontaining non-hydrocarbon impurities which can be employed in the process of the invention are the petroleum hydrocarbon fractions such as gasoline, :naphtha, :kerosene, fuel :oil, gas oil and lubricating=oil fractions which contain minor quantities of nonhydrocarbons such as sulfur, oxygen or nitrogen 'compounds, or mixtures thereof. The quantity of non-hydrocarbons present in such fractions will generally be from about .05 to 8% and usually from .1 to 2%. Such petroleum hydrocarbon oils may have been subjected to various treatments prior to their use in the process of the invention. For example, oils which have been subjected to solvent extraction, acid treatment, clay contacting, and the like, can advantageously be employed.

The quantity of BF to employ is advantageously varied in accordance with the quantity of non-hydrocarbons present in the hydrocarbon material being treated. The quantity of BF should be maintained Within the range of from 0.01 to 10% by Weight of the oil, and usually will be within the range of from 0.05 to 5% by weight of the oil.

The quantity of oxygen to employ does not appear critical, but an excessive quantity should be avoided to prevent oxidation of the hydrocarbons. From about 2 to 8 volumes of oxygen (measured at standard temperature and pressure) per volume of oil, or from about 10 to 40 volumes of air (measured at standard temperature and pressure) per volume of oil, gives good results. In general, a suflicient quantity of oxygen should be used so that further addition thereof does not precipitate any significant quantity of sludge. The oxygen is conveniently introduced by bubbling air through the material being treated, However, other sources of'oxygen such as substantially pure oxygen or oxygen admixed with an inert gas such as nitrogen or carbon dioxide can be used.

The time, temperature and pressure to employ during the BE, and/ or oxygen contacting do not appear critical, except that oxygen should not be contacted with the oil for an excessive time. When the BF, and oxygen are simultaneously contacted with the oil, a time of from 5 to 60 minutes will be employed because of practical considerations. The pressure can be sub-atmos pheric, atmospheric or super-atmospheric, but is advantageously maintained in the range of from atmospheric to 200 p. s. i. g. Preferably ambient temperature is used, but a relatively low temperature, say about 30 F.,

or a relatively high temperature, say about 300 F., can

be advantageously used in some instances. An ele vated temperature is advantageously used, for example, to lower the viscosity of a heavy oil for the BF and/or oxygen contacting. When BF, is first contacted with the oil, followed by contacting with oxygen, reaction conditions substantially equivalent to those above described give good results.

To illustrate an embodiment in the process of the invention, 500 parts by weight of a lubricating oil containing about 0.4% by weight sulfur compounds (calculated as sulfur) is contacted with about 1% by weight BF for about 10 minutes at ambient temperature. A quantity of sludge is formed by this treatment. Air is then bubbled, for about 30 minutes, through the hydrocarbon material containing the sludge, about 25 volumes of air per volume of oil being used. An additional quantity of sludge is formed by contacting with air. Sludge is separated by centrifuging. The separated hydrocarbon material is then washed with water and dried. The resulting product is a refined hydrocarbon oil, stable to oxidation, having a substantially reduced quantity of sulfur compounds.

Theinvention claimed is:

1. Process for refining ahydrocarbon material con-- taining non-hydrocarbons selected from the group consisting of sulfur compounds, oxygen compounds, nitrogen compounds, and mixtures thereof, which comprises contacting said hydrocarbon material with BF and oxygen and separating refined hydrocarbon material from the reaction mixture.

2. Process for refining a petroleum hydrocarbon fraction containing non-hydrocarbons selected from the group consisting of sulfur compounds, oxygen compounds, nitrogen compounds, and mixtures thereof, which comprises contacting said fraction with BF to form a sludge and subsequently contacting the BF treated fraction with oxygen, and separating a refined petroleum hydrocarbon fraction from the reaction mixture.

3. Process for refining a petroleum hydrocarbon fraction containing non-hydrocarbons selected from the group consisting of sulfur compounds, oxygen compounds, nitrogen compounds, and mixtures thereof, which comprises contacting said fraction with BF to form a sludge, separating said sludge from the reaction mixture, contacting the resulting petroleum hydrocarbon fraction with oxygen to form an additional quantity of sludge, and separating a refined petroleum hydrocarbon fraction from the reaction mixture.

4. Process for refining a petroleum hydrocarbon fraction containing non-hydrocarbons selected from the group consisting of sulfur compounds, oxygen compounds, nitrogen compounds, and mixtures thereof, which comprises simultaneously contacting said fraction with BF; and oxygen to form a sludge and separating a refined petroleum hydrocarbon fraction from the reaction mixture.

5. Process for removing sulfur compounds from a petroleum oil which comprises contacting a petroleum oil containing sulfur compounds with from 0.01 to 10% by weight BE, and thereafter contacting the BF treated petroleum oil with from 10 to 40 volumes of air per volume of oil, and separating a petroleum oil having the reduced content of sulfur compounds from the reaction mixture.

6. Process according to claim 5 wherein said petroleum oil containing sulfur compounds is a lubricating oil.

7. Process according to claim 5 wherein said petroleum oil containing sulfur compounds is gasoline.

References Cited in the file of this patent UNITED STATES PATENTS Burk Mar. 7, 1944 Axe Feb. 25, 1947 OTHER REFERENCES 

1. PROCESS FOR REFINING A HYDROCARBON MATERIAL CONTAINING NON-HYDROCARBONS SELECTED FROM THE GROUP CONSISTING OF SULFUR COMPOUNDS, OXYGEN COMPOUNDS, NITROGEN COMPOUNDS, AND MIXTURE THEREOF, WHICH COMPRISES CONTACTING SAID HYDROCARBON MATERIAL WITH BF3 AND OXYGEN AND SEPARATING REFINED HYDROCARBON MATERIAL FROM THE REACTION MIXTURE. 